de0u System Updater download the new release update via OTA > installl it successfully > verified successfully > request user to reboot.
Then I hit reboot > the phone reboots and attempts to apply the release without success for 2 or 3 times as the OP described > then the phone rolls back > then reboots and start being at 2025120401 release.
I have tried same alternatives as the OP (sideloading, changing release channel, wiping updater data, also recently changing date and time to 2 years further) and the result remain the same.